关键词: 中国东北, 那丹哈达地体, 佳木斯地块, 古太平洋板块, 俯冲-增生历史, 构造域转换

Abstract: To reveal the subduction-accretion process of the Paleo-Pacific plate beneath the eastern margin of the Jiamusi block and to clarify the history of tectonic domain transition in Northeast China, this study focuses on reconstructing the subduction-accretion history of ancient oceanic plates. A comprehensive analysis was conducted on the material composition, accretion process, emplacement age, and tectonic setting of the Nadanhada terrane (Nadanhada accretionary complex belt) in Northeast China. The Nadanhada accretionary complex belt is divided into the Yuejinshan and Raohe accretionary complexes. The Yuejinshan accretionary complex is primarily composed of mafic-ultramafic rocks, siliceous rocks, marble, and metaclastic rocks. The mafic-ultramafic rocks formed between the Late Carboniferous and Late Triassic, wherein the protoliths of the metabasalt exhibit geochemical affinities of mid-ocean ridge basalt (MORB) and ocean island basalt (OIB), while the metagabbro originated in an active continental margin setting. The Yuejinshan accretionary complex records two major events: The subduction-accretion of the Panthalassa plate from the Late Carboniferous to Late Triassic, and the initiation of Paleo-Pacific plate subduction from the Late Triassic to Early Jurassic. Its emplacement age (Late Triassic to Early Jurassic) is broadly contemporaneous with the that of the Jilin-Heilongjiang high-pressure belt along the western margin of the Jiamusi block, collectively marking the initiation of the Paleo-Pacific domain in Northeast China. The Raohe accretionary complex constitutes an oceanic island assemblage, whose blocks include Carboniferous-Permian limestone, Middle Triassic-Middle Jurassic siliceous rocks and siliceous shale, Late Triassic-Middle Jurassic mafic-ultramafic rocks. The clastic matrix, which formed from the Middle Jurassic to Early Cretaceous, constrains the timing of accretion for the Raohe accretionary complex. The Raohe accretionary complex was emplaced along the eastern margin of the Yuejinshan accretionary complex in the Early Cretaceous. In summary, the formation of the Nadanhada accretionary complex belt completely records the continuous subduction-accretion history of the Panthalassa and Paleo-Pacific plates beneath the eastern margin of the Jiamusi block from the Late Carboniferous to the Early Cretaceous.

Key words: Northeast China；Nadanhada terrane, Jiamusi block, Paleo-Pacific plate, subduction-accretion history, transition of tectonic domains